Restore Peak Performance to Your GM Vehicle
Is your Chevrolet Express van or GMC truck acting up? Dealing with a persistent Check Engine Light, rough idling, stalling, or a frustrating no-start condition can bring your work or travels to a grinding halt. As a technician with over two decades of experience, I know that the Powertrain Control Module (PCM) is the brain of your vehicle. When it fails, it can cause a cascade of confusing symptoms that are often misdiagnosed. This isn’t just a part; it’s the solution to getting your reliable workhorse back on the road without the exorbitant costs and scheduling headaches of a dealership visit.
This is a reliable, tested OEM Powertrain Control Module that has been carefully sourced. The real value we provide is in the service: we flash this computer with the latest official GM software updates, specifically programmed to your vehicle’s unique Vehicle Identification Number (VIN). This ensures seamless communication between your engine and transmission, restoring the original performance and efficiency. By purchasing this 1998-1999 Express 2500 PCM, you’re getting a part that is ready for installation right out of the box, saving you time, money, and diagnostic frustration.
A Technician’s Notebook: The Ghost in the Machine
I remember a ’99 Suburban that came into my bay with an intermittent stalling problem that was driving the owner crazy. He had already replaced the fuel pump and filter, but the issue persisted. No consistent codes were stored, just an occasional communication error. After checking all the grounds and wiring, we swapped in a known-good PCM. The truck ran perfectly for a week straight. The internal circuits of the original PCM were failing under heat, causing it to randomly cut fuel and spark. It’s a classic failure mode for these modules, and this pre-programmed unit is the exact fix for that kind of elusive problem.
Common Signs of a Failing PCM
If you’re experiencing any of the following, a faulty PCM could be the culprit. A replacement is often the most direct path to a reliable fix.
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine stalls, stumbles, or misfires intermittently.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
Installing your pre-programmed 1998-1999 Express 2500 PCM is a job most DIYers can handle with basic tools. Follow these steps to get your vehicle running again.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most of these GM trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect the Harnesses: Carefully unplug the electrical connectors from the old PCM. There are usually retaining clips that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed PCM into the mounting bracket and securely reconnect the electrical harnesses. You should hear a click as they lock into place.
- Reconnect and Start: Reconnect the negative battery terminal. Your vehicle may require a security relearn procedure (often called Passlock or Passkey), which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual for the specific procedure for your vehicle.
Verified Vehicle Compatibility
This module, identified by service number 16250279 or ID 9355699, is a direct fit for a wide range of GM vehicles. Please match your part number to ensure compatibility. This unit replaces the following part numbers: 09355699, 16266645, 16250279, 16258815, 09366810.
CHEVROLET 2500 PICKUP 98-99 (Gasoline)
CHEVROLET 3500 PICKUP 98-99 (Gasoline)
EXPRESS 1500 VAN 98-99
EXPRESS 2500 VAN 98-99 (Gasoline)
EXPRESS 3500 VAN 98-99 (Gasoline)
SUBURBAN 1500 98-99 (Gasoline)
SUBURBAN 2500 98-99 (Gasoline)
TAHOE 98-99 (Gasoline)
GMC 1500 PICKUP 98-99 (Gasoline)
GMC 2500 PICKUP 98-99 (Gasoline)
GMC 3500 PICKUP 98-99 (Gasoline)
SAVANA 1500 VAN 98-99
SAVANA 2500 VAN 98-99 (Gasoline)
SAVANA 3500 VAN 98-99 (Gasoline)
YUKON 98-99
ASTRO 98
BLAZER S10/JIMMY S15 98
BRAVADA 98
CADILLAC ESCALADE 99
ENVOY 98
ISUZU HOMBRE 98 (4.3L)
SAFARI (GMC) 98
S10/S15/SONOMA 98 (4.3L)
This list is for reference. The most crucial step is providing us with your VIN so we can program this 1998-1999 Express 2500 PCM to match your vehicle’s exact specifications.
Frequently Asked Questions
How do I provide my VIN?
After you complete your purchase, simply send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship the module until we receive this information, as the programming is essential for it to work in your vehicle.
Is this part truly plug-and-play?
Yes, for most vehicles. Because we program it to your VIN, it eliminates the need for a trip to the dealer for flashing. Some GM vehicles may require a simple security relearn procedure that you can do yourself in your driveway. We recommend checking your vehicle’s specific procedure.
Will I need to do a CASE relearn?
A Crankshaft Variation Relearn (CASE) may be necessary to prevent a P1336 trouble code. While the vehicle will run without it, this procedure syncs the PCM with the crankshaft position sensor for optimal misfire detection. Many professional scan tools can perform this function in minutes.
Why choose a used OEM part over a new one?
Used OEM parts offer a fantastic balance of reliability and value. They are the same components your vehicle was built with, ensuring proper fit and function. When paired with our professional VIN-programming service, you get a dependable, cost-effective solution without the high price tag of a new module from the dealer.